Atank contains 135 moles of the monatomic gas argon at a temperature of 15.3 °c. how much energy must be added to the gas to increase its temperature to 45.0 °c?

To calculate the energy required, we will use the following rule:
Q = (3/2)*n*R*ΔT
where:
Q is the amount of energy that we need to calculate
n is the number of moles = 135 moles
R is the gas constant = 8.314
ΔT is the change in temperature = 45 - 15.3 = 29.7 degrees kelvin

Substitute with the givens in the above equation to get the energy as follows:
Q = (3/2) * 135 * 8.314 * 29.7 = 50.00247 * 10^3 Joules